P4a Electrostaics - Sparks
- Specification
- Lesson Plans
- Questions
- Resources
- Extras
Describe and recognise that insulating materials can become charged when rubbed with another insulating material.
State that there are two kinds of charge:
- positive;
- negative.
Describe and recognise that when some materials are rubbed they attract other objects:
- small pieces of paper or cork to a rubbed comb or strip of plastic;
- certain types of dusting brushes become charged and attract dust as they pass over it.
Recognise and describe how you can get an electrostatic shock from charged objects:
- synthetic clothing.
Recognise and describe how you can get an electrostatic shock if you become charged and then become earthed:
- touching water pipes after walking a floor covered with an insulating material e.g. vinyl.
State and recognise that like charges repel and unlike charges attract.
State and recognise that electrostatic phenomena are caused by the transfer of electrons.
Explain how static electricity can be dangerous when:
- in atmospheres where explosions could occur eg inflammable gases or vapours or with high concentrations of oxygen;
- in situations where large quantities of charge could flow through the body to earth.
Explain how static electricity can be a nuisance:
- dirt and dust attracted to insulators (plastic containers, TV monitors etc);
- causing clothing to “cling”.
Describe static electricity in terms of the movement of electrons:
- a positive charge due to lack of electrons;
- a negative charge due to an excess of electrons.
Explain how the chance of receiving an electric shock can be reduced by:
- correct earthing;
- use of insulating mats;
- using shoes with insulating soles.
Explain why it is necessary to earth lorries containing inflammable gases and liquids and powders before unloading.
Explain how anti-static sprays, liquids and cloths help reduce the problems of static electricity.
Objectives:
Understand why materials are normally neutral in terms of basic atomic structure. Charged materials occur because of the transfer of electrons - positive and negative charges due to loss or gain of electrons.
Prior Learning:
basic atomic structure electron proton and neutron
Difficult Concepts:
Creation of positive charge by loss of electrons.
Outline:
atomic structure and neutrality
only electrons move
demo charging up a rod and picking up paper, bending water.
watch glass practical
explain rules for electrostatic force from the results.
Van der Graff generator.
Suggested Practicals:
Electrostatic force - charged polyethene and acetate rods on watch glasses. Make sure they do it. It is magic!
Basic demos of charging and picking up paper pieces and bending water stream and sticking balloon to the wall.
Notes: on structure of atom and charging rods positive and negative in terms of electron flows.
Use Van der Graff generator to demo like charges repel - hair stands on end and idea of charge always seeks out an easy route to Earth/ground. Sparks and shocks.
Extension Activities:
Sparks and ionisation of the air. The complex nature of lightning.
Homework:
Fronter on Benjamin Franklin and the discovery of the nature of lightning.
Objectives:
Dangers associated with static electricity and how to avoid them. Earthing in particular.
Prior Learning:
Nature of static electricity
Difficult Concepts:
Only Earthing.
Outline:
Notes on particular nuisances and dangers outlined especially refueling vehicles.
Explanation of Earthing as a preventative strategy.
Nice chance to look at the Faraday cage.
Charging by friction as the main cause of static build up.
Suggested Practicals:
Van der Graff generator demo of sparking in the dark using the Earthed metal ball as a target.
Extension Activities:
Homework: